European Commission to decide on Rett syndrome drug
DAYBU, also known as trofinetide, has been recommended for approval in the European Union for Rett syndrome after a positive opinion from the Committee for Medicinal Products for Human Use on 26 June 2026. The recommendation covers treatment of neurobehavioral symptoms in adults and children aged five years and older.
If the European Commission grants marketing authorisation in the coming months, DAYBU would become the first treatment approved in the EU for neurobehavioral symptoms of Rett syndrome. The approval would apply across all 27 EU member states, as well as Iceland, Liechtenstein and Norway.
Acadia Pharmaceuticals announced the CHMP opinion after a re-examination procedure. Catherine Owen Adams, Acadia’s chief executive officer, said, “The CHMP’s positive opinion for DAYBU® is an important milestone in our mission to bring this innovative therapy to the EU, where there are no therapies specifically approved for the neurobehavioral symptoms of this devastating condition.”
Trial results behind decision
The committee based its recommendation mainly on the Phase 3 LAVENDER study. According to Acadia, the trial showed statistically significant and clinically meaningful improvements in core features of Rett syndrome on the Rett Syndrome Behaviour Questionnaire and the Clinical Global Impression-Improvement scale.
Those findings suggest DAYBU can address some of the most impactful parts of Rett syndrome, which can severely affect quality of life for patients and caregivers. Pedro Rocha, president of Rett Syndrome Europe, said, “The CHMP’s positive opinion represents hope for thousands of European Union individuals living with this devastating condition, their families and caregivers.”
Rett syndrome is a rare, complex neurodevelopmental disorder that occurs in about one in every 10,000 to 15,000 female births worldwide. A child with Rett syndrome often appears to develop normally at first until six to 18 months, when many skills slow down or stop progressing.
After that early stage, children can enter a period of regression. Families in Europe have had no medicine specifically approved for the neurobehavioral symptoms of the condition for decades, despite the major effect on daily life. The European Commission is expected to issue its final decision in the coming months.
Last updated: 29 June 2026, 11:45 am
